package com.yunxi.gulimall.product.service.impl;

import com.yunxi.common.utils.PageUtils;
import com.yunxi.common.utils.Query;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;

import com.yunxi.gulimall.product.dao.CategoryDao;
import com.yunxi.gulimall.product.entity.CategoryEntity;
import com.yunxi.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Autowired
    private CategoryDao categoryDao;

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        // 查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);
        // 生成树结构
        List<CategoryEntity> level1Menus = entities.stream()
                .filter((categoryEntity -> categoryEntity.getParentCid() == 0))
                .map((menu)->{
                    menu.setChildren(getChildrens(menu, entities));
                    return menu;
                })
                .sorted((menu1,menu2)->{
                    return (menu1.getSort()==null?0:menu1.getSort()) - (menu2.getSort()==null?0:menu2.getSort());
                })
                .collect(Collectors.toList());


        return level1Menus;
    }

    @Override
    public void removeMenuByIds(List<Long> list) {
        //TODO 1、检测当前删除的菜单，是否被引用
        baseMapper.deleteBatchIds(list);
    }

    /**
     * 递归获得树的子类
     * @param root
     * @param all
     * @return
     */
    private List<CategoryEntity> getChildrens(CategoryEntity root, List<CategoryEntity> all) {
        List<CategoryEntity> children = all.stream()
                .filter(categoryEntity -> {
                    return categoryEntity.getParentCid() == root.getCatId();
                })
                .map(categoryEntity -> {
                    categoryEntity.setChildren(getChildrens(categoryEntity, all));
                    return categoryEntity;
                })
                .sorted((menu1,menu2)->{
                    return (menu1.getSort()==null?0:menu1.getSort()) - (menu2.getSort()==null?0:menu2.getSort());
                })
                .collect(Collectors.toList());
        return children;
    }

}